SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '093ea84d9d2497ac1340e497d405d800078431b5cd0942f1e629a561a335c69c' 
  AND token = 'Y+lDVXPCF5tjanxl9K/U7RDWvw/Hv7H27G4kLkHVd04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}